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View Full Version : Finding values of x where the infinite geometric series converge


meeklobraca
Nov4-08, 04:49 PM
1. The problem statement, all variables and given/known data
(2+x)+(2+x)^2+(2+x)^3 + ....


2. Relevant equations





3. The attempt at a solution

Ive found that the l r l < 1

the r of this equation is (2 + x)

so we have -1 < 2 + x < 1

The values of x where the series coverges is -3 < x < -1

Is this correct?

Thanks!

tiny-tim
Nov5-08, 12:30 PM
(2+x)+(2+x)^2+(2+x)^3 + ....

Ive found that the l r l < 1

the r of this equation is (2 + x)

so we have -1 < 2 + x < 1

The values of x where the series coverges is -3 < x < -1

Is this correct?

Thanks!

:rofl: :rofl: :rofl: :rofl:

Hint: does it converge for x = 0? :wink:

gabbagabbahey
Nov5-08, 12:48 PM
1. The problem statement, all variables and given/known data
(2+x)+(2+x)^2+(2+x)^3 + ....


2. Relevant equations





3. The attempt at a solution

Ive found that the l r l < 1

the r of this equation is (2 + x)

so we have -1 < 2 + x < 1

The values of x where the series coverges is -3 < x < -1

Is this correct?

Thanks!

Looks good to me:approve:

meeklobraca
Nov7-08, 12:42 AM
:rofl: :rofl: :rofl: :rofl:

Hint: does it converge for x = 0? :wink:



No I dont think so?

Does your laughing faces mean I got it right? lol

tiny-tim
Nov7-08, 02:51 AM
No I dont think so?

Does your laughing faces mean I got it right? lol

oh dear … I read a -1 as a 1. :redface:

Yes … sorry, meeklobraca … you got it right! :biggrin: